OTTAWA - At Health Canada's request, Nutrabolics Inc. is voluntarily recalling "Blackout," a sleep-aid product, because it is labelled to contain a drug (L-tryptophan) at a prescription-strength dose, and may pose serious health risks. Blackout has not been authorized by Health Canada, which means it has not been evaluated for safety, effectiveness or quality. Prescription drugs should be taken only under the advice and supervision of a healthcare professional because they are used to treat specific diseases and may cause serious side effects. Blackout may have been sold at multiple retailers, both online and in stores, across Canada.